Preface The Association for the Advancement of Medical Instrumentation concerns itself with virtually the complete spectrum of medical measurements and medical devices - the instrumentation involved, the techniques employed, safety, efficacy, and education. Within this broad scope of interest and concern are biomaterials including those used in the fabrication of synthetic implants which are employed to assist or replace body parts. We recognize that biomaterials research is broadly interdisciplinary in nature, requiring medical, surgical, engineering, and materials experts for its advancement. It is necessary that opportunities be provided for these experts to come together to discuss problems, progress, and the potential that biomaterials have in their applications to advances in health care. We welcome, therefore, a collaboration with the National Bureau of Standards and its materials scientists in organizing and conducting technical sessions at our annual meetings to provide the forums for interchange of ideas between the medical, materials, and engineering communities. The present Symposium on Biomaterials was a feature of the Ninth Annual Meeting of AAMI, held in April, 1974 and is the second in a series organized by NBS on this topic. We endorse the cooperation of the National Bureau of Standards in publishing this volume of the Proceedings of the Symposium as one in its series of Special Publications. We feel that this form of publication will contribute to a wide circulation of the volume and we pledge the full cooperation of AAMI in the execution of this worthwhile effort. HAROLD LAUFMAN, M.D. The Association for the Advancement Contents Page K. G. Mayhan, A. W. Hahn, M. R. Havens, and B. W. Peace Plasma-formed polymers for Biomedical Applications. Part II. Biocompatibility and Applica- A. W. Hahn, K. G. Mayhan, J. R. Easley, and C. W. Sanders Interfacial Behavior of Ceramic Implants....... L. L. Hench, H. A. Paschall, W. C. Allen, and G. Piotrowski Soft Tissue Response to a Series of Dense Ceramic Materials and Two Clinically Used W. C. Richardson, S. F. Hulbert, J. J. Klawitter, and B. W. Sauer Engineering and Biological Studies of Metallic Implant Materials ............... Materials Characterization of Implantable Porous Electrodes.... R. B. Beard, J. F. DeRosa, S. F. Dubin, L. Sturm, R. M. Koerner, and A. Miller Properties of Fibrous Biomaterials with Statistically Dispersed Orientation A Simple In Vitro Test for Screening the Blood Compatibility of Materials. H. Kambic, T. Komai, R. J. Kiraly, and Y. Nosé. Conformation of Adsorbed Blood Proteins.... B. W. Morrisey, L. E. Smith, C. A. Fenstermaker, R. R. Stromberg, and W. H. Grant Abstract This volume is based on papers presented at the Symposium on Biomaterials, held in conjunction with the Ninth Annual Meeting of the Association for the Advancement of Medical Instrumentation, New Orleans, La., April 19-20, 1974. It provides a review of special topics in biomaterials research selected to focus attention on some noteworthy achievements. The topics covered include plasma-polymerized polymers and their application in biomedicine; biocompatibility of ceramic materials and their application both as inert coatings for synthetic implants and as porous materials for bone repair; the selection of metallic implant materials through engineering and medical considerations; in vitro testing of thromboresistance; adsorption of blood proteins on synthetic substrates; a prosthesis for nerve regeneration; and properties of fibrous biomaterials. Key words: Biocompatibility; biomaterials; blood protein; ceramic implants; implantable electrodes; metallic implants; nerve prosthesis; synthetic implants; thromboresistance. Introduction Papers published in this Special Publication of the National Bureau of Standards were presented orally at a Symposium on Biomaterials, held in conjunction with the Ninth Annual Meeting of the Association for the Advancement of Medical Instrumentation, New Orleans, La., April 19-20, 1974. The aim of the Symposium and this publication is to review some of the important advances that have been made by the medical profession, materials scientists and engineers, and clinicians in the field of materials used for synthetic implants designed to restore body function and activities to patients. Special topics of general interest were selected for the Symposium in order to focus attention on some noteworthy achievements. Thus, there is reported the plasma-generated synthesis of polymers whose properties are vastly different from those of polymers synthesized by conventional methods and which offer great potential for use in synthetic implants. An intercomparison of the biocompatibility of certain ceramic materials points to the potential of these inert materials to withstand the body environment. A paper on the application of ceramic materials both as ceramic coatings achieved by a unique flame-spray technique and as porous material for bone repair involving bone ingrowth represents an important contribution to biomaterials research. Metals and alloys are discussed from the standpoint of their selection for biomedical application based on engineering and biological considerations, the latter emphasizing systemic effects of metal corrosion products. Thrombogenicity is the subject of two papers, the first describing a reliable in-vitro test system for thromboresistance of materials, the second a report on fundamental studies of adsorption of blood proteins on substitutes, which studies are attempting to elucidate the mechanisms of blood clotting. The fabrication and behavior of implantable porous electrodes are described, work which attempts to decrease polarization losses in galvanic cells used to power pacemakers. The properties of fibrous biomaterials as dependent on orientation of fibers and layers are discussed as applied to the development of composite biomaterials whose properties approach those of bone. The final paper discusses the development and application of a prosthesis which is very successfully used in the regeneration of a severed nerve. In including this symposium in the program of its Ninth Annual Meeting, the Association for the Advancement of Medical Instrumentation is performing an important service to the biomaterials community, as well as to the general public. The Symposium provides a forum for the discussion of progress in research on synthetic implant materials to assist in the development of standards and specification for these materials and improved methods of analysis, characterization and testing leading to improved materials for use by the surgeon to benefit the patient. EMANUEL HOROWITZ JOHN L. TORGESEN Institute for Materials Research |